Calculated aberrations provide useful characterizations of optical system designs. The visualization of particular aberrations over the field of view of optical systems can provide a guide for evaluating and comparing optical system designs. The criticality of different aberrations can vary in accordance with the performance objectives for different types of optical system designs. The effects of changes to the geometry or surface topography of optical surfaces of the optical systems, for example, can be variously reflected in the changes to particular aberrations throughout the modeled optical field.
The emergence of freeform surfaces in imaging optical systems has driven the development of new fabrication methods and mathematical descriptions of surface topography. For example, the introduction of freeform surfaces into optical design has led to the use of nodal aberration theory (NAT) to describe the aberration fields of optical systems that are not constrained to be rotationally symmetric. Full field displays plotting aberrations by type such as wave aberration coefficients, or Zernike polynomial coefficients term-by-term, or summary measures of image quality such as root mean square wavefront error over two spatial dimensions have been used to provide optical designers with insight into the nodal structure of aberrations. The combination of nodal aberration theory and full field displays have been used for evaluating imaging optical designs using rotationally nonsymmetric optical components including freeform surfaces to provide a visual aid for observing the field dependent nodal behavior that appears when the system symmetry is broken.